From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Subject: Re: [PATCH v6 1/4] PCI: Introduce pci_dev_for_each_resource() Date: Thu, 23 Mar 2023 10:02:38 -0500 Message-ID: <20230323150238.GA2550157@bhelgaas> References: Mime-Version: 1.0 Return-path: List-Id: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679583760; bh=A4cz5sAtdGojClghNnzslTTn+0telsrqWPrc7ZEY92A=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=QZ2KDQiDLNeolamz/rBZXmXKaml10w90GcGwB6l5yO87qYFqQPDIQgKZ80zht8Qsc Xeoi/zLrt2EtH3nbngx/R5sYZx0Xwf4JkO9knqHSrKtOYd2+7MSeapV8B/zw9rxmZf 9UhNHPKZpA1ucTpj/VgulfE/ACFQnVZP8YBw36pan4Gf8wwyvTOnEEDjDM2KPQPTQp ZGCnVZCISmiqwx5zKNrKd8Mk7Zh6u/0oYwI8LPRfc1PEUXu67DDtdxfqNx9ryyF1pw 4cNq1h1H67JIwrFngX1Sl9ypuAP/OCB5kx8wJtxg7nOzQYMGU2gbmFC/O67YEr6JCJ aHqE0tG0UVQoQ== Content-Disposition: inline In-Reply-To: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andy Shevchenko Cc: =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= , Mika Westerberg , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Michael Ellerman , Randy Dunlap , Arnd Bergmann , Niklas Schnelle , "Rafael J. Wysocki" , Pali =?iso-8859-1?Q?Roh=E1r?= , "Maciej W. Rozycki" , Juergen Gross , Dominik Brodowski , linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, Miguel Ojeda , Richard On Thu, Mar 23, 2023 at 04:30:01PM +0200, Andy Shevchenko wrote: > On Wed, Mar 22, 2023 at 02:28:04PM -0500, Bjorn Helgaas wrote: > > On Mon, Mar 20, 2023 at 03:16:30PM +0200, Andy Shevchenko wrote: > ... > > > > + pci_dev_for_each_resource_p(dev, r) { > > > /* zap the 2nd function of the winbond chip */ > > > - if (dev->resource[i].flags & IORESOURCE_IO > > > - && dev->bus->number == 0 && dev->devfn == 0x81) > > > - dev->resource[i].flags &= ~IORESOURCE_IO; > > > - if (dev->resource[i].start == 0 && dev->resource[i].end) { > > > - dev->resource[i].flags = 0; > > > - dev->resource[i].end = 0; > > > + if (dev->bus->number == 0 && dev->devfn == 0x81 && > > > + r->flags & IORESOURCE_IO) > > > > This is a nice literal conversion, but it's kind of lame to test > > bus->number and devfn *inside* the loop here, since they can't change > > inside the loop. > > Hmm... why are you asking me, even if I may agree on that? It's > in the original code and out of scope of this series. Yeah, I don't think it would be *unreasonable* to clean this up at the same time so the maintainers can look at both at the same time (this is arch/powerpc/platforms/pseries/pci.c, so Michael, et al), but no need for you to do anything, certainly. I can post a follow-up patch. > > but > > since we're converging on the "(dev, res)" style, I think we should > > reverse the names so we have something like: > > > > pci_dev_for_each_resource(dev, res) > > pci_dev_for_each_resource_idx(dev, res, i) > > Wouldn't it be more churn, including pci_bus_for_each_resource() correction? Yes, it definitely is a little more churn because we already have pci_bus_for_each_resource() that would have to be changed. I poked around looking for similar patterns elsewhere with: git grep "#define.*for_each_.*_p(" git grep "#define.*for_each_.*_idx(" I didn't find any other "_p" iterators and just a few "_idx" ones, so my hope is to follow what little precedent there is, as well as converge on the basic "*_for_each_resource()" iterators and remove the "_idx()" versions over time by doing things like the pci_claim_resource() change. What do you think? If it seems like excessive churn, we can do it as-is and still try to reduce the use of the index variable over time. Bjorn